In this tutorial Molecular dynamics simulation in LAMMPS used to show what happens to a polymer chain at a certain temperature after some time. Chain's movement is caused by a molecular forces between atoms in the chain and by temperature of the chain. This factors are modeled in LAMMPS in order to show the behavior of this polymer chain. The chain was previously prepared in MATLAB. It contains 100 atoms with bound between neghtbour atoms. Duding the simulation, firstly, the chain was left for do deform freely under the molecular forces and a random atomistic fluctation due to the temperature. After that the chain was minimized to find it's minimal energy condition.